A wiper device that moves a driver seat side wiper blade and a passenger seat side wiper blade with a single wiper motor features a linking mechanism that transmits rotary force from the wiper motor to wiper arms. The linking mechanism features a function that, when an external force caused by running wind of the vehicle or the like acts on a wiper blade or wiper arm, inhibits movement of the wiper blade to an unintended position by the external force.
In contrast, wiper devices that move a driver seat side wiper blade and a passenger seat side wiper blade with respectively separate motors often have no linking mechanism between a wiper arm and the wiper motor. In this wiper device, when a wiper blade is subjected to an external force caused by running wind of the vehicle or the like, there is a higher probability of the wiper blade moving to an unintended position than in a wiper device with a linking mechanism.
Japanese Patent No. 5,535,738 discloses the invention of a wiper control apparatus and a wiper device control method in which, when a wiper arm has stopped outside a tolerance range of a stop position due to the action of an external force or the like, a wiper motor is operated and the wiper arm is moved to within the tolerance range of the stop position.
Japanese Patent Application National Publication Nos. 2009-512593 and 2011-512285 disclose the invention of wiper devices in which, even in a state in which an ignition switch of a vehicle has been switched off, a wiping angle of a wiper is periodically detected. If the wiping angle has changed from a target position, a motor turns and the wiping angle is set to the target position.